A conveyor of this type is known which, for example, is used to transport rolled profile beams in a rolling mill in a horizontal transport direction perpendicular to the length of the beams from the end of the rolling line to a temporary storage location or another treatment stage. Normally a plurality of transverse conveyors are provided that operate synchronously and that all extend parallel to one another from an input conveyor to an output conveyor.
A known such conveyor (see U.S. Pat. No. 4,440,292) has a horizontal rail extending in the direction and having an upper rail surface and a carriage riding on the rail and displaceable in the direction along the rail. A pair of similar end links spaced apart in the direction are pivotal on the carriage about respective generally parallel support axes extending horizontally generally perpendicular to the direction and spaced apart in the direction. A lifting member is pivoted on the end links at respective member axes generally parallel to and offset from the support axes and has an upper horizontal member surface. A lower link pivoted on the end links at lower axes generally parallel to and offset from the respective member axes forms a parallelogrammatic linkage with the lifting member and end links. This linkage is movable between a raised position with the upper member surface above the rail and a lowered position with the upper member surface below the upper rail surface. A spring engaged with the linkage urges same into the lower position.
A flexible element spanned over front and rear wheels at the respective ends of the rail has a front end operatively connected to the carriage and a rear end secured to one of the end links at a location offset from the respective support axis. A drive can tension the element downstream relative to the normal transport direction to pull the carriage in the transport direction, and can tension the element upstream of the carriage to pivot the end links between the raised and lowered positions.
In addition the lifting member is provided with upstanding stops that project above the upper rail surface in the raised and lower positions of the linkage. Thus the carriage can be moved in the transport direction while in the lowered position to engage these stops against the downstream edge of a workpiece, thereby aligning the workpiece on the transverse-conveyer rails by sliding it a short distance in the transport direction until it engages all the stops of the synchronously moving transverse conveyors. Then the lifting member is raised to pick up the aligned workpiece and carry it with substantially less friction and work forward to the downstream end of the rail.
Even if the parallelogrammatic linkage is set up to allow the stops to be dropped below the workpiece-support plane defined by the upper surface of the rail, this requires a very substantial vertical displacement of the lifting member between uppermost and lowermost positions, and requires that this large displacement be made each time the carriage is returned opposite the normal transport direction. Once thus dropped it is then necessary to again raise the lifting member to engage the stops with the downstream workpiece edge.